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W1ll
Asked: 2020-11-16 15:31:48 +0800 CST 2020-11-16 15:31:48 +0800 CST

Error when passing a string from an Android navigation bar to another activity

  • 772

I am trying to pass a string variable from one activity to another activity without success, this is my data:

Inside Activity1 I have this String: stringInfoUSB and this intent

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
.
.
final UsbDevice device = driver.getDevice();
final String stringInfoUSB = String.format("Driver: %s  Vendor: %s Product: %s",driver.getClass().getSimpleName(),
                HexDump.toHexString((short) device.getVendorId()),
                HexDump.toHexString((short) device.getProductId()));
.
.
.
@Override
public boolean onNavigationItemSelected(MenuItem item) {

    int id = item.getItemId();

    if (id == R.id.nav_usb) {
        Intent intent = new Intent(this, UsbInfoActivity.class);
        intent.putExtra("infoUSB", stringInfoUSB);
        startActivity(intent);
    }

This is the activity2 that receives the variable:

public class UsbInfoActivity extends AppCompatActivity {
private Button mBotonCancel;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate( savedInstanceState );
    setContentView( R.layout.activity_usb_info );

    Bundle bundle = getIntent().getExtras();                        
    String textoImportado1=bundle.getString("Info_USB");

    mBotonCancel = (Button)findViewById( R.id.bt2_SendButton ) ;

    String bufferTexto2 = textoImportado1;
    TextView mDumpTextView = (TextView)findViewById(R.id.tv2_ReadValues);
    mDumpTextView.setText(bufferTexto2);

    mBotonCancel.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent2 = new Intent(v.getContext(), MainActivity.class);
            startActivityForResult(intent2, 0);
        }
    });

}

I need to send this string to the activity2 called UsbInfoActivity, after selecting an item from a navigation bar, but stringinfoUSB gives me ERROR!, can someone tell me what error?

android

2 Answers

  1. Best Answer

    First you have an error when sending the text, you are writing the key incorrectly:

     intent.putExtra("infoUSB", stringInfoUSB);

    and you try to receive it

    String textoImportado1=bundle.getString("Info_USB");

    you must receive it with the same key that you send it:

    String textoImportado1=bundle.getString("info_USB");

    Second, I recommend you define the variables, but evaluate to onCreate()or in this case on onNavigationItemSelected()their values:

    private UsbDevice device;
private String stringInfoUSB;
...
...  
@Override
public boolean onNavigationItemSelected(MenuItem item) {

    device = driver.getDevice();
    stringInfoUSB = String.format("Driver: %s  Vendor: %s Product: %s",driver.getClass().getSimpleName(),
                HexDump.toHexString((short) device.getVendorId()),
                HexDump.toHexString((short) device.getProductId()));

    int id = item.getItemId();

    if (id == R.id.nav_usb) {
        Intent intent = new Intent(this, UsbInfoActivity.class);
        intent.putExtra("infoUSB", stringInfoUSB);
        startActivity(intent);
    }
    • 1

  2. The detail is that the variable you are trying to send "infoUSB" is not the same as the one you are trying to retrieve "Info_USB", both must be the same variable in your first Activity you have intent.putExtra( "infoUSB" , stringInfoUSB); therefore in your second Activity it must be the same String textoImportado1=bundle.getString( "infoUSB" );

    • 0